• 폴리머
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• 제25권3호
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• pp.385-390
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• 2001

oxyethylene/oxypropylene 공중합체의 존재하에 L-lactide를 중합시킴에 의해 poly(L-lactic acid) (PLLA) (A)와 polyether (B)로 이루어진 A-B-A block copoly(ester-ether)를 합성하였으며, 이들 블록 공중합체는 세그멘트를 도입함에 의해 PLLA에 유연성이 부여되었고, 표면에서의 미세상분리 구조로 인한 항혈전성의 개질을 확인하기 위하여 AFM사진을 관찰한 결과, PLLA와 비교하여 블록 공중합체는 필름표면의 요철성이 현저하게 저하하여 매끄러운 것을 확인하였으며 따라서, 표면의 요철이 항혈전성의 증가와 깊은 관계가 있음을 확인하였다.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2007년도 학술발표회 논문집
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• pp.257-258
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• 2007

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• Macromolecular Research
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• 제17권9호
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• pp.682-687
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• 2009

Nanofibrous membranes of poly(D,L-lactic acid)/chitin blend were prepared by electro spinning for a barrier of guided tissue regeneration. A miscible solution was obtained by the blending chitin-salt complex into 1-methyl-2-pyrrolidone solution of poly(D,L-lactic acid). The properties of the blend were examined for nanofibrous fabrication. The viscosity of the blend solution was increased significantly due to chain entanglement despite the low ratio of chitin to poly(D,L-lactic acid). An interaction between two polymeric compositions was confirmed by Fourier transform infrared spectroscopy. X-ray diffraction detected an appreciably ordered microstructure in the nanofiber of the blend. A membrane of thinner nanofibers was fabricated by electro spinning the chitin blend. The permeability of the membranes was examined using bioactive model compounds.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.227.2-228
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• 2003

In many biodegradable polymers recently investigated, poly(lactic acid)(PLA) or poly(lactic-co-glycolic acid)(PLGA) have extensively been utilized as drug delivery systems for sustained release drug delivery. Recently, there has been increased interest in electrospinning, which can produce fibers that are sub-micron in diameter. This technique has been applied to various micro/nano fabrication areas using numerous polymers but very few uses in the sharmaceutical area have been reported. (omitted)

• 폴리머
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• 제24권3호
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• pp.431-436
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• 2000

폴리락트산의 열적 안정성과 기계적 물성을 개선하고자 측쇄에 벤젠고리를 함유한 천연 $\alpha$-히드록시산인 만델린산(mandelic acid)과 L-락트산을 직접 용액 축중합법으로 공중합체를 합성하고 그 열적, 물리적 성질 등을 조사하였다. 합성된 공중합체는 무정형이었으며, 만델린산의 함량이 증가할수록 유리전이온도와 분해개시온도가 상승함을 열분석을 통해 알 수 있었다. 또한 만델린산을 5, 10 wt% 함유한 공중합체의 필름의 경우 그 기계적 성질이 다소 향상된 결과를 얻었다.

• Journal of Pharmaceutical Investigation
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• 제26권1호
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• pp.13-22
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• 1996

Poly(D,L-lactic acid) (PLA) microspheres containing alprazolam(APZ) were prepared by a solvent-emulsion evaporation method and their release patterns were investigated in vitro. Various batches of microspheres with different size and drug content were obtained by changing the ratio of APZ to PLA, PLA concentration in the dispersed phase and stirring rate. Rod-like APZ crystals on microsphere surface, which were released rapidly and could act as a loading dose, were observed with increasing drug content. The release rate was increased with increase in drug contents and decrease in the molecular weight of PLA. The release rate of APZ for long-acting injectable delivery system in vitro, which would aid in predicting in vitro release profile, could be controlled by properly optimizing various factors affecting characteristics of microspheres.

• 폴리머
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• 제33권2호
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• pp.164-168
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• 2009

본 연구는 화학적으로 개질된 열가소성 전분(chemically modified thermoplastic starch(CMPS))과 poly(lactic acid)(PLA)와 poly(butylene adipate-co-terephthalate)(PBAT) 블렌드의 형태학, 열적 및 기계적 특성에 미치는 영향에 대해서 연구하였다. PLA/PBAT 블렌드에 CMPS를 이 블렌드의 중량기준으로 10, 20, 30 wt%를 첨가하여 이축압출기로 가공하였다. PLA/PBAT/CMPS 블렌드에서 PLA의 유리전이온도($T_g$)는 CMPS 함량이 증가하여도 큰 변화를 나타내지 않았지만, CMPS의 첨가에 의해 PLA상과 PBAT상 사이의 계면상태가 좋아지는 상용성 있는 형태학을 보여주었다.

• 한국염색가공학회:학술대회논문집
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• 한국염색가공학회 2006년도 임시총회 및 추계학술발표회
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• pp.38-40
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• 2006

• KSBB Journal
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• 제30권4호
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• pp.161-165
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• 2015

Lactic acid and its derivatives are widely used in the food, pharmaceutical, and cosmetic industries. It is also a major raw material for the production of poly-lactic acid (PLA), a biodegradable and environmentally friendly polymer and a possible alternative to synthetic plastics derived from petroleum. For PLA production by new strains of lactic acid bacteria (LAB), we screened LAB isolates from shellfish. A total of 51 LAB were isolated from 7 types of shellfishes. Lactic acid production of individual isolates was examined using high-performance liquid chromatography using a Chiralpak MA column and an ultraviolet detector. Lactobacillus plantarum T-3 was selected as the most stress-resistant strain, with minimal inhibition concentrations of 1.2 M NaCl, 15% ethanol, and 0.0020% hydrogen peroxide. In a 1 L fermentation experiment, $\small{D}$-lactic acid production of 19.91 g/L fermentation broth was achieved after 9 h cultivation, whereas the maximum production of total lactic acid was 41.37 g/L at 24 h.

• 대한화학회지
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• 제34권2호
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• pp.203-210
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• 1990

의약 전달체에 사용되는 생체분해성 고분자로서 L-lactic acid 와 L-glutamic acid가 각기 다른 조성비로 이루어진 공중합체를 합성하였다. Poly (L-lactide)는 zink oxide를 이용하여 합성하였으며, Poly (L-lactide) 말단에 3-Amino-l-propanol을 도입시킨 다음 이미 합성된 γ-benzyl-L-glutamate-N-carboxyanhydride (γ-BLG-NCA)를 개환중합시켜서 block copoly (L-lactide-γ-benzyl-L-glutamate)를 합성하였다. NMR로써 L-lactide와 γ-BLG-NCA가 서로 일정한 비율로 이루어진 공중합체가 합성되었음을 확인하였으며, 생성된 공중합체들의 열적성질은 시차주사열량계법 및 열무게 측정법으로 조사하였다.